Unless otherwise indicated herein, the description in this section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section.
Conventionally, the following image forming apparatus has been known. The typical image forming apparatus converts input color values such as RGB values into output color values such as CMYK values. Then, the typical image forming apparatus performs printing using a color material such as toner by an amount according to the converted output color values. Different from printing in a normal mode, there has been known a conventional image forming apparatus that can perform printing in a reduction mode, which reduces a consumption of toner.
Here, the following method (hereinafter referred to as a “gamma-control type reduction method”) to reduce the consumption of the toner has been known. The typical method controls one-dimensional input-output property (gamma values) of respective toner of cyan, magenta, yellow, and black. That is, the typical method compresses respective C values, M values, Y values, and K values of the CMYK values as the output color values by an identical ratio. Thus, the typical method reduces the consumption of the entire toner of the cyan, magenta, yellow, and black.
The following another method (hereinafter referred to as an “input color value change type reduction method”) to reduce the consumption of the toner has been known. The other typical method compresses a color gamut of the input color values such as the RGB values, that is, the other typical method changes the input color values. Thus, the other typical method reduces the consumption of the toner.